A gas turbine engine (“GTE”) is known to include one or more stages of turbine rotor assemblies mounted on a drive shaft. Each turbine rotor assembly includes a plurality of turbine blades extending radially outward and spaced circumferentially from one another around a turbine rotor. The GTE ignites a mixture of air/fuel to create a flow of high-temperature compressed gas over the turbine blades, which causes the turbine blades to rotate the turbine rotor assembly. Rotational energy from each turbine rotor assembly may be transferred to the drive shaft to power a load, for example, a generator, a compressor, or a pump.
A turbine blade typically includes a root structure and an airfoil extending from opposite sides of a turbine blade platform. The turbine rotor is known to include a slot for receiving each turbine blade. The shape of each slot may be similar in shape to the root structure of each corresponding turbine blade. When a plurality of turbine blades are assembled on the turbine rotor, an under-platform cavity may be formed between and/or beneath turbine platforms of adjacent turbine blades. An ingress of high-temperature compressed gas into the under-platform cavity through a gap between adjacent turbine blade platforms may cause premature fatigue of turbine blades due to excessive heat.
Various systems and components for regulating the flow of compressed gas around turbine rotor assemblies are known. Some systems are known to utilize a damper positioned between turbine blades to regulate the flow of gas within a turbine rotor assembly. Further, it is known to use a moveable element to bridge the gap between adjacent turbine blade platforms. In some cases, it is also known to utilize a damper in combination with a moveable element.
One example of a system including a seal body positioned between adjacent turbine blades to regulate a flow of gases around a turbine rotor stage is described in U.S. Pat. No. 7,097,429 to Athans et al. (“the '429 patent”). The '429 patent discloses a rotor disk including a plurality of turbine blades. Each turbine blade includes an airfoil, a platform, and a shank. The shank may extend down to a multilobe dovetail to mounted the turbine blade to the rotor disk. The seal body is positioned between the shanks and below the platforms of adjacent turbine blades. The seal body includes an enlarged seal plate disposed at a forward end of the seal body. The enlarged plate overlaps forward faces of adjacent shanks to provide a seal. The seal body also seals at an aft end with a rectangular head disposed above a pair of axial lobes or tangs. The enlarged plate includes a small inlet aperture for metering a small amount of purge air between the shanks during operation to control the disk temperature.
Although the system of the '429 patent may disclose using a seal body between shanks of adjacent turbine blades, certain disadvantages persist. For example, the seal body of the '429 patent discloses small head on the aft end that may be prone to gas leakage. Further, the seal body of the '429 patent does not permit a flow of cooling gas to be regulated around an outer edge of the enlarged seal plate at the forward face of the turbine shanks.